Electric resistance



March 7, 1933. slLBERsTElN I 1,900,205

ELECTRIC RESISTANCE Filed June 28, 1929 3 res onding parts. In said drawing,

Patented Mar. 7, 1933 UNITED STATES- ISIDOB srnnnnsr'mn, or BERLIN, onamamr ELECTRIC RESISTANCE Application filed June 25, 1929,!erial No. 374,376, and in Germany. June 30, 192.8.

My inventionrelates to improvements in electric resistances, and more particularly in electric resistances consisting of solid rods and the construction of the connection of the leads thereto. The object of the improve- -ments'is to provide a connection for electric resistances which is reliable after long use,

and which can be made without spoilingthe resistance or the coating thereof. With thls 13 object in view myinventionconsists in providin the resistance with a metallic end piece or en pieces constructed for having the leads connected thereto by ressi'ng parts of the metal on the leads. n the preferred embodiment of the invention I providethe said metallic end. piece or end pieces with a groove 1 is an elevation of the resistance having two leads connected thereto,

' ig..2 is a detail sectional elevation on an enlarged scale showing one of the ends of the 3 resistance and the metal piececarried thereby, Fig.3 is an end'view looking from the left.

in Fig; 2,

Fig. 4 is an elevation showing a modification in which the resistance is carried by elastic arms,

Fig. 5 is anelevation showing another modification,

Fig/dis a sectional view on an enlarged scale showing a modified form of the end 40 piece,- and /Fig. 7 is an end view looking from the left in Fig.6.

In the exam 1e shown in Figs. 1 to3 a resistance rod o. as-end pieces inthe form of cylindricalpxips b secured thereto. The rodia ismade'from glassor other ceramic material,"

and itiscoated at' both endswith layers o of copper or otherv high conductive material insuringya reliable electrical connection between-the caps b andniatter of lowconduccontacts of a radio apparatus or the like.

tivity carried by the-rod a. In the example."

shown in the figures the said matter consists.

of a linear strip d'of carbon coated b a layer e of lacquer indicated in Fig. 2 y .crosshatching? 65 Each cap I; is'made integral with an axial extension f, and it is formed with an annular groove g. In the manufacture of the resistance the caps b are placed on the co percoated ends of the rod a, the leads are formed with eyes, and the said eyes are embedded in the grooves g. Now the is brought on a press having slightly conical matrices and adapted to press the caps 6 into close contact with the ends ofthe rod. Siinultaneously b the said matrices the margins 11 of the caps are pressed inwardly, thus firmly pressing the eyes of theleads into the grooves g. Preferably the leads hare tinned at their ends so that a reliable joint'is roduced between the same and the walls 0 the grooves g.

In the practical useof the resistance the free ends of the leads k may be soldered to the If desired the leads h may be cut from the caps 12, and the resistance may be fitted b means of the extensions f between contacts. made in the form of leaf springs and placed on a foundation m, as is shown in Fig. 4.

In the modification shown in Fi s. 5 to 7 in lieu of the grooves 9 formed in t e caps 6 rings n are fitted on the extensions f of thecaps b, and the said ringsare formed with annular glrooves o for securing the leads h thereto, t c said leads being formed at their ends with e es embedded'in the said grooves" and pressed into contact therewith by bending the mar inal parts p of the rin 1|, inwardly. A ter thus securing the Wire h to the ring 11. the said .ring is pressed on the extension f. v

By thus fixing the leads h to a separate ring n the said ring-and the cap 15 may be made from difiere'nt' materialsaccording to 96:

the desired use ofthe resistance. For example the ring .n may be made from softfmetaii- I sothat themargin p canbe readily presse into enga ment with the lead h for ressing f the same into the groove 0'. The cap may be 100' 

